My point was focused on poverty understood relatively. Yes, the improvement in human technology/productivity has, across many centuries, increased the total output per person-hour of labor. Some of that improvement has trickled down to the mass of people. They lived better with settled agriculture than as nomads, with feudalism rather than slavery, with capitalism rather than slavery or feudalism, and so on. But there were exceptions and occasional reversals.
Marx's insight was to see how capitalism not only stimulated rapid technological/productivity increases but also reproduced the social dichotomy between rich and poor. It was, as he said, as good at reproducing poverty as at reproducing wealth; it reproduced unequal divisions of wealth and income.
That is why, despite countless anti-poverty programs across the history of capitalism, poverty always returns to characterize the system. Capitalism reproduces relative poverty by its nature, its functioning, its system.